1. Field of the Invention
The present invention relates to a droplet jetting head configured to jet droplets.
2. Description of the Related Art
A droplet jetting applicator is used for printing image information and also in a process for forming a color filter, a black matrix, a conductive film, and the like, in manufacturing various flat display devices such as a liquid crystal display device, an organic EL (electro luminescence) display device, an electron emission display device, a plasma display device or an electrophoretic display device. This droplet jetting applicator includes a droplet jetting head (such as an inkjet head) for jetting liquid such as ink as droplets from multiple nozzles. The droplet jetting head makes the droplets land on application targets, sequentially forms dot arrays in a predetermined pattern, and thereby manufactures various coated bodies.
The droplet jetting head is configured to change volumes of multiple liquid chambers for containing liquid by use of multiple piezoelectric elements, and to jet the liquid in those liquid chambers from respective nozzles, i.e. nozzle orifices. The droplet jetting head includes a liquid chamber plate (an intermediate plate) having the liquid chambers, and a nozzle plate for connecting those liquid chambers and the nozzle orifices, respectively (see JP-A No. 2005-270743, for example). Here, the piezoelectric elements are arranged in two straight lines and the adjacent piezoelectric elements are arranged away from each other at a pitch of a minimum distance required to avoid interference with each other.
However, when the piezoelectric elements are arranged in the two straight lines at the pitch of the minimum distance as described above, new piezoelectric elements cannot be provided between the adjacent piezoelectric elements in order to increase the number of nozzles. Thus, it is impossible to reduce the pitch of the nozzle orifices. For this reason, when the number of the nozzles is increased, the droplet jetting head extends in the direction of arrangement of the nozzle orifices. That leads to a size increase of the droplet jetting head.